/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2009 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions;
import org.exist.dom.QName;
import org.exist.xquery.AnalyzeContextInfo;
import org.exist.xquery.Cardinality;
import org.exist.xquery.CompiledXQuery;
import org.exist.xquery.Constants;
import org.exist.xquery.Dependency;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
/**
* Built-in function fn:lang().
*
*/
public class FunLang extends Function {
public static String queryString = "(ancestor-or-self::*/@xml:lang)[position() = last()]";
public CompiledXQuery query;
protected static final String FUNCTION_DESCRIPTION_1_PARAM =
"Tests whether the language of the context item ";
protected static final String FUNCTION_DESCRIPTION_2_PARAMS =
"Tests whether the language of $node ";
protected static final String FUNCTION_DESCRIPTION_BOTH =
"as specified by xml:lang attributes is the " +
"same as, or is a sublanguage of, the language specified by $lang. The " +
"behavior of the function if the second argument is omitted is exactly the " +
"same as if the context item (.) had been passed as the second argument. The " +
"language of the argument node, or the context item if the second argument is " +
"omitted, is determined by the value of the xml:lang attribute on the node, " +
"or, if the node has no such attribute, by the value of the xml:lang attribute " +
"on the nearest ancestor of the node that has an xml:lang attribute. If there " +
"is no such ancestor, then the function returns false().\n\n" +
"The following errors may be raised: if the context item is undefined [err:XPDY0002]XP; " +
"if the context item is not a node [err:XPTY0004]XP.\n\n" +
"If $lang is the empty sequence it is interpreted as the zero-length string.";
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName("lang", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_1_PARAM + FUNCTION_DESCRIPTION_BOTH,
new SequenceType[] {
new FunctionParameterSequenceType("lang", Type.STRING, Cardinality.ZERO_OR_ONE, "The language code")
},
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.ONE, "true if the language code matches, false otherwise")
),
new FunctionSignature(
new QName("lang", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_2_PARAMS + FUNCTION_DESCRIPTION_BOTH,
new SequenceType[] {
new FunctionParameterSequenceType("lang", Type.STRING, Cardinality.ZERO_OR_ONE, "The language code"),
new FunctionParameterSequenceType("node", Type.NODE, Cardinality.EXACTLY_ONE, "The node")
},
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.ONE, "true if the language code matches, false otherwise")
)
};
public FunLang(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
super.analyze(contextInfo);
query = context.getBroker().getXQueryService().compile(context, queryString);
}
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
if (contextItem != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());
}
if (contextItem != null)
contextSequence = contextItem.toSequence();
if (getArgumentCount() == 2)
contextSequence = getArgument(1).eval(contextSequence);
if (contextSequence == null)
throw new XPathException(this, "XPDY0002: Undefined context item");
Sequence result;
if (!(Type.subTypeOf(contextSequence.getItemType(), Type.NODE)))
throw new XPathException(this, "XPDY0004: Context item is not a node");
else {
String lang = getArgument(0).eval(contextSequence).getStringValue();
Sequence seq = query.eval(contextSequence);
if (seq.isEmpty()) {
result = BooleanValue.FALSE ;
} else if (seq.hasOne()) {
String langValue = seq.getStringValue();
boolean include = lang.equalsIgnoreCase(langValue);
if (!include) {
int hyphen = langValue.indexOf('-');
if (hyphen != Constants.STRING_NOT_FOUND) {
langValue = langValue.substring(0, hyphen);
include = lang.equalsIgnoreCase(langValue);
}
}
result = new BooleanValue(include);
}
else
throw new XPathException(this, "XPDY0004: Sequence returned more than one item !");
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
/* (non-Javadoc)
* @see org.exist.xquery.functions.Function#getDependencies()
*/
public int getDependencies() {
return Dependency.CONTEXT_SET;
}
}